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ADU Ordinance & Updates Archive

The City of San José enacts state legislation pertaining to ADUs in the City’s zoning code, and the City's ADU Universal Checklist is maintained to reflect current state laws and local regulations.

This webpage serves only to document changes to ADU regulations in recent years and may not include the most recent changes. 

2020 ADU ORDINANCE CHANGES

The City Council voted on April 14, 2020 to update San Jose's zoning code to allow for tiny homes on wheels (THOWs), which are a type of detached ADU, going into effect on May 29, 2020. Please read Bulletin 291-Tiny Home on Wheels Permit Checklist for more information.

The California Department of Housing and Community Development’s Accessory Dwelling Unit Handbook also reflects the status of ADUs as of 2020. As of 2024, some of the rules expressed are outdated.

2019 ADU Ordinance Changes

The City Council voted on Dec. 17, 2019 to update San José's zoning code to align with California State laws on ADUs that went into effect on Jan. 1, 2020. The table below shows the changed regulations. THIS TABLE DOES NOT REFLECT CURRENT REGULATIONS, WHICH HAVE EVOLVED FURTHER SINCE 202O. For the most current ADU regulations, please view the City's ADU Universal Checklist.

Item City's Regulation BEFORE DEC. 17, 2019 City's updated REGULATIONS To Align with State laws effective Jan. 1, 2020
Effective Date City Council approved the regulations below on July 27, 2018 with subsequent updates approved on May 23, 2019; June 25, 2019; and November 19, 2019. On December 17, 2019, City Council approved the following changes, effective immediately upon their vote on Dec. 17, 2019.
Zoning District

ADUs are allowed:

 

• In R-1, R-2, and R-M zoning districts on lots that have one single-family residence.

 

• In Planned Development (PD) districts that are subject to R-1 standards and uses OR where ADUs are not expressly prohibited.

 

• In a low-density cluster development if it conforms to development standards of the R-1 zoning district, and the development and use standards of the low-density cluster permit.

ADUs are allowed:

 

• In R-1, R-2, and R-M zoning districts on lots that have one single-family residence.

 

• On lots with a single-family residence In Planned Development (PD) districts that are subject to R-1 standards and uses OR the ADU conforms to the development and use standards of the PD district.

 

• On any lot with an existing single-family dwelling unit, where regardless of zoning, the lot has any of the following General Plan Land Use/Transportation designations:

- Residential Neighborhood

- Mixed-Use Neighborhood

- Urban Village or Urban Residential

- Transit Residential or Rural Residential

- Downtown

- Mixed-Use Commercial

 

• On two-family (duplex) lots and on multifamily properties

 

• In a low-density cluster development if it conforms to development standards of the R-1 zoning district, and the development and use standards of the low-density cluster permit.

 
Minimum Lot Size 3,000 square feet No minimum lot size
Minimum Setbacks from Rear and Side Property Lines 0 feet for 1-story conversions and new construction. 

5 feet for second-story ADUs constructed above a garage or accessory structure. 		0 feet for 1-story conversions and new construction. 

4 feet for second-story ADUs constructed above a garage or accessory structure

4 feet minimum rear and side setbacks required for detached ADU in multifamily developments.
Maximum Height

For detached ADUs: 

Single story – 18 feet maximum 
Second story – 24 feet maximum  

Attached ADUs are subject to the height limits of the main home.

Single-family properties - No change in height requirements.

 

Multifamily properties - 16 feet maximum height for detached ADUs.
Rear Yard Coverage Area covered by the ADU, accessory buildings, and accessory structures, except pools, shall not exceed forty percent (40%) of the rear yard. Area covered shall not exceed forty percent (40%) of the rear yard or up to 800 square feet, whichever is greater.
Detached ADU Allowed Locations

Rear yard only, at least 6 feet away from primary dwelling. 

 

May be attached to a detached garage or other existing accessory structure.

 

Must meet minimum setbacks for an accessory building in accordance with Section 20.30.500. 

 No changes except that ADUs that exceed forty percent (40%) of the rear yard must maintain minimum 4 foot side and rear setbacks. One-foot overhang for eaves would be allowed.
ADU Size (in sf)
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 600
5,445 - 9,000 700
9,001 - 10,000 800
10,001 - Up 900
Lot Size (sf) ADU Maximum Size (sf)
Up to 9000 1,000
9,000 and greater
 1,200
Number of Bedrooms and Bathrooms Two bedrooms allowed on lots with an area greater than 9,000 square feet, and only one bathroom. Up to two bedrooms and two bathrooms allowed for all units.
Attached ADU Maximum Floor Area May not exceed 50% of the existing or proposed primary dwelling living area. May not exceed 50% of the existing or proposed primary dwelling living area or 800 square feet, whichever is greater.
Design Standards Visual compatibility with existing primary dwelling is required. No design standards, except new simplified standards for attached ADU units for historic buildings listed in the Historic Resources Inventory.
Parking requirements An ADU requires 1 space unless the property qualifies for an exemption under State law—see the parking requirements.

If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. Parking spaces may be configured on-site per state law.		 No change in parking requirements for the ADU.

Replacement parking for garages and carports converted to ADUs will not be required.
Junior ADU
(JADU)		 Not allowed. Allow JADU up to 500 square feet within the existing walls of a single-family home. Must include at least an efficiency kitchen. May share a bathroom with the primary unit. Owner-occupancy and deed restriction will be required, subject to State law regulations.

2018 ADU Ordinance Changes

Based on public input and public hearings before the Planning Commission, in mid-2018 the City Council approved updates to Section 20.30 of the Zoning Code to ease requirements for ADUs. The changes are now expressed in Section 20.30.150 of the Zoning Ordinance. The table below reflects the changes.

Item Regulation prior to July 27, 2018 Regulation Effective July 27, 2018
Zoning District ADUs allowed in R-1, R-2, and PD (subject to R-1 standards) zoning districts, which are comprised of single-family residences. Additionally allow ADUs in R-M zoning districts, and in any Planned Development (PD) district where ADUs are not expressly prohibited. Development standards of the Municipal Code and of planned developments zones apply in all cases.
Minimum Lot Size 5,445 sf 3,000 sf
Minimum Setbacks from Rear and Side Property Lines 0 feet – Conversions 5 feet – New construction 0 feet – 1-story conversions 5 feet – New construction or for ADUs constructed above a garage or accessory structure.
Maximum Height Single story – 18 feet maximum No 2nd-story unit allowed Single story – 18 feet maximum 2nd-story allowed – 22 feet maximum*
*Either an ADU atop a garage or accessory structure or a two-story ADU.
Rear Yard Coverage Not including pools, not more than 40% of the rear yard may be covered. No change
Detached ADU Location Rear yard only, at least 6 feet away from primary dwelling, attached only to a detached garage. Rear yard only, at least 6 feet away from primary dwelling, attached to a detached garage or other existing accessory structure.
ADU Size (in sf)
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 Not allowed
5,445 - 9,000 600
9,001 - 10,000 650
10,001 - Up 800
Lot Size (sf) ADU Maximum Size (sf)
3,000 - 5,444 600
5,445 - 9,000 700
9,001 - 10,000 800
10,001 - Up 900
Number of Bedrooms Studio or 1 bedroom Under 800 sf: Studio or 1 bedroom allowed 800 sf and up: 2 bedrooms maximum allowed
Attached ADU Maximum Floor Area May not exceed 50% of the existing primary dwelling living area May not exceed 50% of the existing or proposed primary dwelling living area
Design Standards Match appearance, and match roof form and pitch Require visual compatibility with existing primary dwelling.
Parking requirements Parking configurations in conformance with State law An ADU requires 1 space unless the property qualifies for an exemption under State law—see Parking section of webpage. If a garage has been converted, the main dwelling parking space must be replaced, as uncovered or in front or side setback areas. The homeowner may apply for a reduction of one space of required parking. Parking spaces may be configured on-site per State law.
Reduction in required off-street parking spaces No more than one dwelling occupies the lot. (Section 20.90.220) No more than one dwelling, in conjunction with an ADU , occupies the lot.
Junior ADU Not allowed Removed from consideration; not part of the approved ordinance.
Front yard paving No more than 50% of the front setback may be paved with any impervious surface. (Section 20.30.440) No more than 50% of the front setback may be paved with any impervious or pervious surface.
ADU requirements for lots in Historic Resources Inventory Requires Single-Family House Permit Waive requirement for a Single-Family House Permit for detached ADU or for conversion of existing accessory structure with no exterior alterations.